When a fuel pump plunger sticks due to seizure it is necessary to lift the plunger and the barrel and fit a spare one. The pump barrels and plungers are mated together and hence not interchangeable.. The barrel and the plunger are lifted together in the assembled position by an extractor. The extractor is screwed with the plunger by the central rod. The barrel is bolted with the flange of the extra .The same tool is used for mounting a new set of barrel and plunger.